package com.neo.util;

import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Map;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.Binarizer;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.EncodeHintType;
import com.google.zxing.LuminanceSource;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.Result;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

public class QRCodeUtil extends LuminanceSource {    
    
    private static final Logger logger = LoggerFactory.getLogger(QRCodeUtil.class);  
  
    // 二维码颜色  
    private static final int BLACK = 0xFF000000;  
    // 二维码颜色  
    private static final int WHITE = 0xFFFFFFFF;  
  
    private final BufferedImage image;  
    private final int left;  
    private final int top;  
  
    public QRCodeUtil(BufferedImage image) {  
        this(image, 0, 0, image.getWidth(), image.getHeight());  
    }  
  
    public QRCodeUtil(BufferedImage image, int left, int top, int width, int height) {  
        super(width, height);  
        int sourceWidth = image.getWidth();  
        int sourceHeight = image.getHeight();  
        if (left + width > sourceWidth || top + height > sourceHeight) {  
            throw new IllegalArgumentException("Crop rectangle does not fit within image data.");  
        }  
        for (int y = top; y < top + height; y++) {  
            for (int x = left; x < left + width; x++) {  
                if ((image.getRGB(x, y) & 0xFF000000) == 0) {  
                    image.setRGB(x, y, 0xFFFFFFFF); // = white  
                }  
            }  
        }  
        this.image = new BufferedImage(sourceWidth, sourceHeight, BufferedImage.TYPE_BYTE_GRAY);  
        this.image.getGraphics().drawImage(image, 0, 0, null);  
        this.left = left;  
        this.top = top;  
    }  
  
    @Override  
    public byte[] getRow(int y, byte[] row) {  
        if (y < 0 || y >= getHeight()) {  
            throw new IllegalArgumentException("Requested row is outside the image: " + y);  
        }  
        int width = getWidth();  
        if (row == null || row.length < width) {  
            row = new byte[width];  
        }  
        image.getRaster().getDataElements(left, top + y, width, 1, row);  
        return row;  
    }  
  
    @Override  
    public byte[] getMatrix() {  
        int width = getWidth();  
        int height = getHeight();  
        int area = width * height;  
        byte[] matrix = new byte[area];  
        image.getRaster().getDataElements(left, top, width, height, matrix);  
        return matrix;  
    }  
  
    @Override  
    public boolean isCropSupported() {  
        return true;  
    }  
  
    @Override  
    public LuminanceSource crop(int left, int top, int width, int height) {  
        return new QRCodeUtil(image, this.left + left, this.top + top, width, height);  
    }  
  
    @Override  
    public boolean isRotateSupported() {  
        return true;  
    }  
  
    @Override  
    public LuminanceSource rotateCounterClockwise() {  
        int sourceWidth = image.getWidth();  
        int sourceHeight = image.getHeight();  
        AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, sourceWidth);  
        BufferedImage rotatedImage = new BufferedImage(sourceHeight, sourceWidth, BufferedImage.TYPE_BYTE_GRAY);  
        Graphics2D g = rotatedImage.createGraphics();  
        g.drawImage(image, transform, null);  
        g.dispose();  
        int width = getWidth();  
        return new QRCodeUtil(rotatedImage, top, sourceWidth - (left + width), getHeight(), width);  
    }  
  
    /** 
     * @param matrix 
     * @return 
     */  
    private static BufferedImage toBufferedImage(BitMatrix matrix) {  
        int width = matrix.getWidth();  
        int height = matrix.getHeight();  
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);  
        for (int x = 0; x < width; x++) {  
            for (int y = 0; y < height; y++) {  
                image.setRGB(x, y, matrix.get(x, y) ? BLACK : WHITE);  
            }  
        }  
        return image;  
    }  
  
    /** 
     * 生成二维码图片 
     *  
     * @param matrix 
     * @param format 
     * @param file 
     * @throws IOException 
     */  
    public static void writeToFile(BitMatrix matrix, String format, File file) throws IOException {  
        BufferedImage image = toBufferedImage(matrix);  
        if (!ImageIO.write(image, format, file)) {  
            throw new IOException("Could not write an image of format " + format + " to " + file);  
        }  
    }  
  
    /** 
     * 生成二维码图片流 
     *  
     * @param matrix 
     * @param format 
     * @param stream 
     * @throws IOException 
     */  
    public static void writeToStream(BitMatrix matrix, String format, OutputStream stream) throws IOException {  
        BufferedImage image = toBufferedImage(matrix);  
        if (!ImageIO.write(image, format, stream)) {  
            throw new IOException("Could not write an image of format " + format);  
        }  
    }  
  
    /** 
     * 根据内容，生成指定宽高、指定格式的二维码图片 
     * 
     * @param text   内容 
     * @param width  宽 
     * @param height 高 
     * @param format 图片格式 
     * @return 生成的二维码图片路径 
     * @throws Exception 
     */  
    private static String generateQRCode(String text, int width, int height, String format, String pathName)  
            throws Exception {  
        Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();  
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");// 指定编码格式  
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);// 指定纠错等级  
        hints.put(EncodeHintType.MARGIN, 1); // 白边大小，取值范围0~4  
        BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);  
        File outputFile = new File(pathName);  
        writeToFile(bitMatrix, format, outputFile);  
        return pathName;  
    }  
  
    /** 
     * 输出二维码图片流 
     *  
     * @param text 二维码内容 
     * @param width 二维码宽 
     * @param height 二维码高 
     * @param format 图片格式eg: png, jpg, gif 
     * @param response HttpServletResponse 
     * @throws Exception 
     */  
    public static void generateQRCode(String text, int width, int height, String format, HttpServletResponse response)  
            throws Exception {  
        Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();  
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");// 指定编码格式  
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);// 指定纠错等级  
        hints.put(EncodeHintType.MARGIN, 1); // 白边大小，取值范围0~4  
        BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);  
        writeToStream(bitMatrix, format, response.getOutputStream());  
    }  
  
    /** 
     * 解析指定路径下的二维码图片 
     * 
     * @param filePath 二维码图片路径 
     * @return 
     */  
    public static String parseQRCode(String filePath) {  
        String content = "";  
        try {  
            File file = new File(filePath);  
            BufferedImage image = ImageIO.read(file);  
            LuminanceSource source = new QRCodeUtil(image);  
            Binarizer binarizer = new HybridBinarizer(source);  
            BinaryBitmap binaryBitmap = new BinaryBitmap(binarizer);  
            Map<DecodeHintType, Object> hints = new HashMap<DecodeHintType, Object>();  
            hints.put(DecodeHintType.CHARACTER_SET, "UTF-8");  
            MultiFormatReader formatReader = new MultiFormatReader();  
            Result result = formatReader.decode(binaryBitmap, hints);  
  
            logger.info("result 为：" + result.toString());  
            logger.info("resultFormat 为：" + result.getBarcodeFormat());  
            logger.info("resultText 为：" + result.getText());  
            // 设置返回值  
            content = result.getText();  
        } catch (Exception e) {  
            logger.error(e.getMessage());  
        }  
        return content;  
    }  
  
    public static void main(String[] args) {  
        String text = "王伟发红包，扫者有份！"; // 随机生成验证码  
        System.out.println("随机码： " + text);  
        int width = 200; // 二维码图片的宽  
        int height = 200; // 二维码图片的高  
        String format = "png"; // 二维码图片的格式  
  
        try {  
            // 生成二维码图片，并返回图片路径  
            String pathName = generateQRCode(text, width, height, format, "D:/new.png");  
            System.out.println("生成二维码的图片路径： " + pathName);  
  
            String content = parseQRCode(pathName);  
            System.out.println("解析出二维码的图片的内容为： " + content);  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
    }  
    
}
